AIDS stands for Acquired Immune Deficiency Disease. It is caused by a virus. The disease originated somewhere in Africa about 30 years ago. There it first appeared as a mysterious ailment afflicting primarily heterosexuals of both sexes. It probably was spread primarily by female prostitutes there. AIDS has already become a crisis of stagg...
'' Isolated in their own worlds, people with autism appear indifferent and remote. They are normally unable to form emotional bonds with others. Although people with this brain disorder can display a wide range of symptoms and disabilities, many are incapable of understanding other people's thoughts, feelings, and needs. Often, their langu...
It has long been believed that the largest entity brought upon the Earth by humankind is the Pyramid of the Sun, constructed in Mexico around the start of the Christian era. The mammoth structure commands nearly thirty million cubic feet of space. In contrast, however, is the Durham Road Landfill, outside San Francisco, which o...
One of the scariest emotional experiences a person can ever suffer during their lifetime is to experience a form of depression. Over one in five Americans can expect to get some form of depression in their lifetime. Over one in twenty Americans have a depressive disorder every year. Depression is one of the most common and most serious menta...
Science , ancient art practiced especially in the Middle Ages, devoted chiefly to discovering a substance that would transmute the more common metals into gold or silver and to finding a means of indefinitely prolonging human life. Although its purposes and techniques were dubious and often illusory, alchemy was in many ways the predecessor of...